15 Most Actively Traded ETFs

Volatility and uncertainty are abounding in financial markets so far this year. Rather than being paralyzed by fear, traders are embracing the big moves. Trading action across exchanges has spiked amid this year's stock market rout.

Volume—a measure of how many shares trade hands on a given day—is averaging 4.8 billion, year-to-date. That compares with an average of 3.7 billion for all of 2015.

This isn't unusual. Volume tends to increase during market downturns as some traders head for the hills while other hunt for bargains.

SPY Leads, UWTI Close Behind

What's true in the aggregate is also true on an individual security basis, with stocks and exchange-traded funds across the board seeing higher-than-normal volume.

(Keep in mind that, regarding ETFs, volume is distinct from fund flows, which are derived from the creation and redemption of shares. Trading of existing shares with no change to an ETF's shares outstanding affects volume but not flows).

In terms of ETFs, the most actively traded fund is no surprise. This year, the SPDR S&P 500 (SPY | A-98) is far and away the volume leader, as it typically is, with an average of 185 million shares traded each day during the past 30 days.

Meanwhile, the iShares MSCI Japan ETF (EWJ | B-97) has seen big volume as traders debate whether the Bank of Japan's recent move to cut interest rates into negative territory will be successful in reinvigorating the Japanese economy.

VIX & Gold Miner Products PopularWith volatility on the rise, another group of products that's been popular among traders this year is volatility ETNs. The most noteworthy of the bunch is the iPath S&P 500 VIX Short-Term Futures ETN (VXX | B-47), which trades nearly 97 million shares a day on average.

The VIX tends to rise when stock markets are falling; thus, traders who buy VXX and similar products are effectively betting on continued losses in stocks.

Of course, simply measuring the volume of shares that trade hands for a particular ETF doesn't tell the whole story. All else equal, cheaper-priced funds tend to have more shares traded because investors can simply buy more for a given amount of money.

Dollar volume, which measures the number of shares traded multiplied by the share price, gives a more complete view of how much money is exchanging hands in a security.

Using this measure, once again, SPY leads the pack, with more than $35.2 billion worth of shares trading daily so far this year.

With only $290 million worth of shares traded daily, UWTI doesn't come close to cracking the top 15 dollar-volume leaders. A minimum-daily-dollar volume of about $1.15 billion is necessary to make this list.